Mystery House, On-Line Systems' (Sierra) first release, was the first adventure game to feature graphics. Published in May 1980, the game is already well-documented on other gaming sites. However, the first release of the game is very rare (and has been the subject of speculation).

As confirmed by Ken and Roberta Williams, the first edition of Mystery House consisted of a small blue card with a diskette, packaged in a clear plastic bag.

Ken Williams: "Cool! I haven't seen this in a LONG time! That's the VERY first packaging. Roberta and I couldn't afford typesetting so we cut/pasted words from magazines." Roberta adds: "That's my handwriting! I wrote that '48K Req' thing. That is a VERY early copy. In fact, I see that it was 'typeset' (if you want to use that word) by me -- look how 'neat and clean' the lines are on the typesetting. I remember doing that."

Probably no more than 1000 copies of that particular packaging were sold.